NFTSMC-BASED ROBUST CONTROL APPROACH FOR AUTONOMOUS SPACECRAFT RENDEZVOUS

In this paper, the problem of uncertain autonomous spacecraft rendezvous is studied using disturbance observer and nonsingular fast terminal sliding mode control (NFTSMC) techniques. Taking the accuracy of spacecraft rendezvous process into account, a disturbance observer is designed to identify the external disturbance and parameter uncertainty, which affect the spacecraft attitude stability, and the obtained estimation will be used to the compensation part design of the rendezvous controller. And then, a continuous NFTSMC-based robust control scheme is developed with the aid of Lyapunov stability criteria, which could achieve the better rendezvous performance than some existing results; the finite time stability of the closed loop system is analyzed using Lyapunov approach. Finally, a simulation example is given to illustrate the superiority of the designed scheme.